Initial oxidation of CuInSe2

The oxidation of p-type single-crystal and thin-film polycrystalline CuInSe2 is investigated using complementary Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS) and x-ray photoelectron spectroscopy (XPS). The compositions of the thermally-grown oxides over the 150 °–300 °C temperature range are found to be primarily In2O3, with some SeO2, estimated to be less than 10% by quantitative AES and XPS. The interface between the oxide and CuInSe2 is examined using AES and SIMS depth-compositional profiling in conjunction with XPS. CuxSe is found to form at the interface. Angular-resolved XPS with an in situ oxidation process is utilized to evaluate the initial oxidation of this Cu-ternary semiconductor. These studies confirm that CuxSe forms during oxide growth.